KASAN: invalid memory access in checkalias

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 275dedaf93b0 drm/amdgpu: tear down userq mgr and eviction ..
git tree: https://github.com/blackgnezdo/openbsd-src.git syzbot-kasan
console output: https://syzkaller.appspot.com/x/log.txt?x=10fa10b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=85e25e37d09e1b88
dashboard link: https://syzkaller.appspot.com/bug?extid=afdc4e6c81edf41b242f

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7c4ef6ece368/disk-275dedaf.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/f37413fa5768/bsd-275dedaf.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ae4a84e28f1c/kernel-275dedaf.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+afdc4e...@syzkaller.appspotmail.com

panic: Caught invalid memory access at ffffffff85327ef4 size 4 op 0
Stopped at db_enter+0x17: popq %rbp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
*363557 56287 0 0 0x4000000 0K syz-executor
db_enter() at db_enter+0x17 sys/arch/amd64/amd64/db_interface.c:457
panic(ffffffff846334c7) at panic+0x270 sys/kern/subr_prf.c:198
__asan_load4_noabort(ffffffff85327ef4) at __asan_load4_noabort+0xa3
checkalias(ffff800001780988,ffff6783,ffff800000d80800) at checkalias+0x482 sys/kern/vfs_subr.c:608
ffs_vinit(ffff800000d80800,ffff80003bbbff00) at ffs_vinit+0x237 sys/ufs/ffs/ffs_subr.c:-1
ffs_vget(ffff800000d80800,665b,ffff80003bbc00c0) at ffs_vget+0x748 sys/ufs/ffs/ffs_vfsops.c:1285
ufs_lookup() at ufs_lookup+0x15c1 sys/ufs/ufs/ufs_lookup.c:573
VOP_LOOKUP(ffff800001a251d0,ffff80003bbc09a0,ffff80003bbc09d0) at VOP_LOOKUP+0xda sys/kern/vfs_vops.c:85
vfs_lookup(ffff80003bbc0970) at vfs_lookup+0xfbd sys/kern/vfs_lookup.c:580
namei(ffff80003bbc0970) at namei+0xe19 sys/kern/vfs_lookup.c:250
vn_open(ffff80003bbc0970,10001,0) at vn_open+0x240 sys/kern/vfs_vnops.c:146
doopenat(ffff80003bbc3780,ffffff9c,200000000040,10000,0,0,ffff80003bbc0cd0) at doopenat+0x460 sys/kern/vfs_syscalls.c:1163
sys_open(ffff80003bbc3780,ffff80003bbc0cd0,ffff80003bbc0c40) at sys_open+0x86 sys/kern/vfs_syscalls.c:1065
syscall(ffff80003bbc0cd0) at syscall+0x1089 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003bbc0cd0) at syscall+0x1089 sys/arch/amd64/amd64/trap.c:783
end trace frame: 0xffff80003bbc0d50, count: 0
https://www.openbsd.org/ddb.html describes the minimum info required in bug
reports. Insufficient info makes it difficult to find and fix bugs.


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